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//===- AssumeBundleQueries.cpp - tool to query assume bundles ---*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/AssumeBundleQueries.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/DebugCounter.h"
#define DEBUG_TYPE "assume-queries"
using namespace llvm;
using namespace llvm::PatternMatch;
STATISTIC(NumAssumeQueries, "Number of Queries into an assume assume bundles");
STATISTIC(
NumUsefullAssumeQueries,
"Number of Queries into an assume assume bundles that were satisfied");
DEBUG_COUNTER(AssumeQueryCounter, "assume-queries-counter",
"Controls which assumes gets created");
static bool bundleHasArgument(const CallBase::BundleOpInfo &BOI, unsigned Idx) {
return BOI.End - BOI.Begin > Idx;
}
static Value *getValueFromBundleOpInfo(AssumeInst &Assume,
const CallBase::BundleOpInfo &BOI,
unsigned Idx) {
assert(bundleHasArgument(BOI, Idx) && "index out of range");
return (Assume.op_begin() + BOI.Begin + Idx)->get();
}
bool llvm::hasAttributeInAssume(AssumeInst &Assume, Value *IsOn,
StringRef AttrName, uint64_t *ArgVal) {
assert(Attribute::isExistingAttribute(AttrName) &&
"this attribute doesn't exist");
assert((ArgVal == nullptr || Attribute::isIntAttrKind(
Attribute::getAttrKindFromName(AttrName))) &&
"requested value for an attribute that has no argument");
if (Assume.bundle_op_infos().empty())
return false;
for (auto &BOI : Assume.bundle_op_infos()) {
if (BOI.Tag->getKey() != AttrName)
continue;
if (IsOn && (BOI.End - BOI.Begin <= ABA_WasOn ||
IsOn != getValueFromBundleOpInfo(Assume, BOI, ABA_WasOn)))
continue;
if (ArgVal) {
assert(BOI.End - BOI.Begin > ABA_Argument);
*ArgVal =
cast<ConstantInt>(getValueFromBundleOpInfo(Assume, BOI, ABA_Argument))
->getZExtValue();
}
return true;
}
return false;
}
void llvm::fillMapFromAssume(AssumeInst &Assume, RetainedKnowledgeMap &Result) {
for (auto &Bundles : Assume.bundle_op_infos()) {
std::pair<Value *, Attribute::AttrKind> Key{
nullptr, Attribute::getAttrKindFromName(Bundles.Tag->getKey())};
if (bundleHasArgument(Bundles, ABA_WasOn))
Key.first = getValueFromBundleOpInfo(Assume, Bundles, ABA_WasOn);
if (Key.first == nullptr && Key.second == Attribute::None)
continue;
if (!bundleHasArgument(Bundles, ABA_Argument)) {
Result[Key][&Assume] = {0, 0};
continue;
}
auto *CI = dyn_cast<ConstantInt>(
getValueFromBundleOpInfo(Assume, Bundles, ABA_Argument));
if (!CI)
continue;
uint64_t Val = CI->getZExtValue();
auto Lookup = Result.find(Key);
if (Lookup == Result.end() || !Lookup->second.count(&Assume)) {
Result[Key][&Assume] = {Val, Val};
continue;
}
Lookup->second[&Assume].Min = std::min(Val, Lookup->second[&Assume].Min);
Lookup->second[&Assume].Max = std::max(Val, Lookup->second[&Assume].Max);
}
}
RetainedKnowledge
llvm::getKnowledgeFromBundle(AssumeInst &Assume,
const CallBase::BundleOpInfo &BOI) {
RetainedKnowledge Result;
Result.AttrKind = Attribute::getAttrKindFromName(BOI.Tag->getKey());
if (bundleHasArgument(BOI, ABA_WasOn))
Result.WasOn = getValueFromBundleOpInfo(Assume, BOI, ABA_WasOn);
auto GetArgOr1 = [&](unsigned Idx) -> uint64_t {
if (auto *ConstInt = dyn_cast<ConstantInt>(
getValueFromBundleOpInfo(Assume, BOI, ABA_Argument + Idx)))
return ConstInt->getZExtValue();
return 1;
};
if (BOI.End - BOI.Begin > ABA_Argument)
Result.ArgValue = GetArgOr1(0);
if (Result.AttrKind == Attribute::Alignment)
if (BOI.End - BOI.Begin > ABA_Argument + 1)
Result.ArgValue = MinAlign(Result.ArgValue, GetArgOr1(1));
return Result;
}
RetainedKnowledge llvm::getKnowledgeFromOperandInAssume(AssumeInst &Assume,
unsigned Idx) {
CallBase::BundleOpInfo BOI = Assume.getBundleOpInfoForOperand(Idx);
return getKnowledgeFromBundle(Assume, BOI);
}
bool llvm::isAssumeWithEmptyBundle(AssumeInst &Assume) {
return none_of(Assume.bundle_op_infos(),
[](const CallBase::BundleOpInfo &BOI) {
return BOI.Tag->getKey() != IgnoreBundleTag;
});
}
static CallInst::BundleOpInfo *getBundleFromUse(const Use *U) {
if (!match(U->getUser(),
m_Intrinsic<Intrinsic::assume>(m_Unless(m_Specific(U->get())))))
return nullptr;
auto *Intr = cast<IntrinsicInst>(U->getUser());
return &Intr->getBundleOpInfoForOperand(U->getOperandNo());
}
RetainedKnowledge
llvm::getKnowledgeFromUse(const Use *U,
ArrayRef<Attribute::AttrKind> AttrKinds) {
CallInst::BundleOpInfo* Bundle = getBundleFromUse(U);
if (!Bundle)
return RetainedKnowledge::none();
RetainedKnowledge RK =
getKnowledgeFromBundle(*cast<AssumeInst>(U->getUser()), *Bundle);
if (llvm::is_contained(AttrKinds, RK.AttrKind))
return RK;
return RetainedKnowledge::none();
}
RetainedKnowledge
llvm::getKnowledgeForValue(const Value *V,
ArrayRef<Attribute::AttrKind> AttrKinds,
AssumptionCache *AC,
function_ref<bool(RetainedKnowledge, Instruction *,
const CallBase::BundleOpInfo *)>
Filter) {
NumAssumeQueries++;
if (!DebugCounter::shouldExecute(AssumeQueryCounter))
return RetainedKnowledge::none();
if (AC) {
for (AssumptionCache::ResultElem &Elem : AC->assumptionsFor(V)) {
auto *II = dyn_cast_or_null<AssumeInst>(Elem.Assume);
if (!II || Elem.Index == AssumptionCache::ExprResultIdx)
continue;
if (RetainedKnowledge RK = getKnowledgeFromBundle(
*II, II->bundle_op_info_begin()[Elem.Index])) {
if (V != RK.WasOn)
continue;
if (is_contained(AttrKinds, RK.AttrKind) &&
Filter(RK, II, &II->bundle_op_info_begin()[Elem.Index])) {
NumUsefullAssumeQueries++;
return RK;
}
}
}
return RetainedKnowledge::none();
}
for (const auto &U : V->uses()) {
CallInst::BundleOpInfo* Bundle = getBundleFromUse(&U);
if (!Bundle)
continue;
if (RetainedKnowledge RK =
getKnowledgeFromBundle(*cast<AssumeInst>(U.getUser()), *Bundle))
if (is_contained(AttrKinds, RK.AttrKind) &&
Filter(RK, cast<Instruction>(U.getUser()), Bundle)) {
NumUsefullAssumeQueries++;
return RK;
}
}
return RetainedKnowledge::none();
}
RetainedKnowledge llvm::getKnowledgeValidInContext(
const Value *V, ArrayRef<Attribute::AttrKind> AttrKinds,
const Instruction *CtxI, const DominatorTree *DT, AssumptionCache *AC) {
return getKnowledgeForValue(V, AttrKinds, AC,
[&](auto, Instruction *I, auto) {
return isValidAssumeForContext(I, CtxI, DT);
});
}
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